Pregnancy Week 21: Your Baby's Moves and Your Midwife Appointments

8 min read

Quick answer: At 21 weeks your baby weighs around 360 grams and measures about 26.7cm from crown to heel. Tell your midwife if you have not felt your baby move by 24 weeks. There is no set number of movements to feel each day, so learn your baby's own pattern and contact your midwife immediately if movements reduce or change. If this is your first pregnancy, your next routine appointments are usually around 25 and 28 weeks.

What parents need to know

Week 21 brings you further into the heart of the second trimester. Your baby's movements are becoming more regular and distinctive, and you're settling into a rhythm of antenatal appointments that will continue throughout your pregnancy. This week is a good time to think about your birth plan and preferences for your baby's arrival.

The Crib

Your baby at 21 weeks

Baby's length, size comparison, next appointments and what happens at 28 weeks

Around 26.7cm crown to heel

Approximately 360 grams

Roughly the size of a carrot

Baby's length: around 26.7cm crown to heel

Next appointments: around 25 and 28 weeks (first pregnancy)

At 28 weeks: blood test for anaemia; anti-D if Rhesus negative

Sources: NHS, Tommy's, NCT, RCOG. General information, not medical advice.

How big is your baby at 21 weeks?

Your baby now weighs approximately 360 grams and measures around 26.7cm from crown to heel, roughly the size of a carrot. They're becoming more and more of a real, individual presence.

What's happening with your baby?

Your baby's eyebrows and eyelids are now fully formed. Their lips are becoming more defined. The digestive system continues to practise, with your baby swallowing amniotic fluid regularly. The pancreas, which will eventually produce insulin and digestive enzymes, is steadily developing.

Your baby's sleep cycles are becoming more established, and you may notice periods of activity followed by periods of quiet. Many babies are most active when their mother is still, as movement during the day can lull them to sleep. So if you notice increased movement at night when you're trying to sleep, this is perfectly normal.

Your baby may also be responding to sounds from outside the womb. Loud, sudden noises can cause a startle response. Playing music, talking, and reading aloud are all ways to bond with your baby during pregnancy.

A baby with curious eyes touches a glass surface indoors.

Monitoring baby's movements

You should start to feel your baby move between 16 and 24 weeks. If this is your first baby, you might not feel movements until after 20 weeks. If you have not felt your baby move by 24 weeks, tell your midwife. There is no set number of movements you should feel each day — every baby has their own normal pattern. The important thing is to get to know what's normal for your baby, and to contact your midwife immediately if you notice a reduction in movements or a change in your baby's usual pattern. Never wait until the next day to report reduced movements. Call your midwife or maternity unit straight away, even if it's the middle of the night. They'll need to check your baby's movements and heartbeat.

Planning for the birth: beginning to think about your preferences

It's not too early to start thinking about your birth preferences, even if a formal birth plan feels like something for later in pregnancy. Some questions worth reflecting on include: Where would you like to give birth? (Options typically include a hospital obstetric unit, a midwife-led unit, or a home birth.) Who would you like as your birth partner(s)? What are your thoughts on pain relief options? Are there any cultural or personal preferences that are important to you?

Your midwife will discuss birth preferences with you at a later appointment, usually around 34 to 36 weeks, and will help you record them. The NCT has excellent resources to help you think through your options.

Antenatal appointments in the second trimester

If this is your first pregnancy, your next routine appointments after the 20-week scan will typically be at around 25 and 28 weeks. At 28 weeks, you will be offered another blood test to check for anaemia and to recheck your blood group. Women who are Rhesus negative will be offered anti-D injections at around 28 weeks to prevent complications in this or future pregnancies.

When to get help

Some symptoms in pregnancy can be a sign of something serious and need checking quickly. This is who to contact, and how soon.

Call 999 if:

you're bleeding from your vagina and the bleeding is heavy (soaking a period pad soon after putting it on), or you also have severe pain in your tummy, pain in your shoulder, or feel sick, faint, dizzy or lose consciousness
you think your baby is coming now and you have a strong urge to push (ask for an ambulance)
you have severe difficulty breathing (you're gasping, choking or not able to get words out) or your chest feels tight or heavy
you have pain and swelling in one leg and you also feel short of breath or have chest pain. A blood clot in the leg can travel to your lungs, which can be life-threatening
you have possible signs of sepsis, such as breathing very fast, being confused or having slurred speech, blue, pale or blotchy skin, a rash that does not fade when you press it, or a very high or very low temperature. Being pregnant makes sepsis more likely
you do not feel you can keep yourself safe (a mental health emergency is as serious as a physical one)

Always call 999 if you think it's a life-threatening emergency, no matter what stage of pregnancy you are.

Call your midwife or maternity unit now if:

your baby is moving less than usual, you cannot feel your baby moving anymore, or there is a change to your baby's usual pattern of movements
you have light bleeding or spotting, even if you have no pain or only mild tummy pain
you have stomach pain that is severe or does not go away after you've rested for 30 to 60 minutes, or stomach pain with regular cramping or tightenings, lower back pain, or pain when you pee
you're less than 37 weeks pregnant and you have a gush or trickle of fluid from your vagina (this could be your waters breaking), regular contractions or tightenings, period-type pains, or backache that's not usual for you
you have signs of pre-eclampsia: a severe headache that does not go away with simple painkillers, vision problems (such as blurred vision or seeing flashing lights), pain below the ribs, sudden swelling of the face, hands or feet, feeling very unwell, heartburn that does not go away with heartburn medicines, or being sick (vomiting)
your skin is very itchy (for example, it keeps you awake at night), the palms of your hands or soles of your feet are itchy, or the itching is worse at night. This can be a sign of a liver condition called intrahepatic cholestasis of pregnancy (ICP) that needs urgent treatment
your breathlessness comes on suddenly, you're out of breath when you're lying down, or you're breathless and also have chest pain or feel dizzy
you have pain or swelling in one leg, usually in the calf or thigh. This could be a blood clot (deep vein thrombosis, or DVT), which is more likely when you're pregnant
you have a high temperature (38C or above), or you feel hotter than usual or shivery. A high temperature can be a sign of an infection, so it's important to get it checked

If your baby's movements change, do not wait until the next day: call immediately, even if it's the middle of the night. Do not use a home doppler to check the heartbeat yourself. Even if you hear a heartbeat, this does not mean your baby is well.

If you cannot reach them, or you're not sure what to do, call NHS 111.

Speak to your midwife or GP if:

you have not felt your baby move by 24 weeks. Most people start to feel movements between 16 and 24 weeks. If this is your first baby, you might not feel them until after 20 weeks
you're worried about your mental health, or stress, anxiety or low mood are affecting your day-to-day life. If you need urgent help for your mental health, call 111 and select the mental health option, or ask for an urgent GP appointment

Your week 21 checklist

This week:

Start tuning in to your baby's movement pattern.
Begin thinking about birth preferences.
Look into local birth options (hospital, midwife-led unit, home birth).
Continue regular exercise and pelvic floor exercises.
Contact your midwife without hesitation if you notice any reduction in movements.

Frequently asked questions

How many movements should I feel at 21 weeks?

There is no set number of movements to feel each day. Every baby has their own pattern, so the aim is to learn what is normal for your baby and use it as a baseline.

Why is my baby more active at night?

Many babies are most active when their mother is still, because daytime movement can lull them to sleep. Increased movement at night when you are trying to sleep is perfectly normal.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.